<https://www.bryansmithblogs.com/what-is-the-purpose-of-holter-monitor-test-sydney/>
<http://schema.org/description>
"A Holter monitor is a portable device that measures and records your heart's activity (ECG) continuously for 24 to 72 hours or longer"
<https://www.bryansmithblogs.com/what-is-the-purpose-of-holter-monitor-test-sydney/>